Electro-optical device and electronic apparatus

ABSTRACT

An electro-optical device of the present invention includes pixel electrodes, TFTs electrically connected to the pixel electrodes, and scanning lines and data lines connected to the TFTs on a TFT array substrate. Each scanning line has a broad width portion as a gate electrode in a portion facing a channel area of the TFT and the narrow width portion. As a result, an electro-optical device capable of easily adjusting an arrangement of the gate electrodes and the scanning lines and at the same time precisely driving the TFTs is provided.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to an electro-optical device capable ofperforming active matrix drive. The invention also relates to anelectronic apparatus incorporating such an electro-optical device.

2. Description of Related Art

The related art includes an electro-optical device including a pair ofsubstrates constructed to sandwich an electro-optical material, such asa liquid crystal, therebetween and electrodes provided in each of thepair of substrates to apply an electric field to the electro-opticalmaterial. The electrodes are used to apply an electric field to theelectro-optical material to vary the state of the material. According tosuch an electro-optical device, for example, when the light emitted froma light source enters the device and the state of the electro-opticalmaterial is varied, it is possible to control the light transmittanceand thus realize desired image display.

Moreover, in related art electro-optical devices, by providing pixelelectrodes arranged in a matrix shape, thin-film transistors(hereinafter “TFT”) connected to the respective pixel electrodes, andscanning lines and data lines connected to each of TFTs and provided inparallel to a row direction and a column direction, respectively, on oneof the pair of substrates, active matrix drive can be performed. As aresult, for each pixel defined by the pixel electrodes or the scanninglines and the data lines, it is possible to control the electric fieldapplied to the electro-optical material and to control the lighttransmittance.

SUMMARY OF THE INVENTION

However, in the related art electro-optical devices, there are thefollowing problems. That is, for an electro-optical device capable ofperforming the above active matrix drive, it is required to preciselydrive the TFTs. However, precisely driving the TFTs is a difficult taskwhile satisfying the high precision and miniaturization requirementsimposed in related art electro-optical devices.

A TFT includes a semiconductor layer having a channel area, a sourcearea and a drain area, and a gate electrode formed through an insulatingfilm to cover at least a part of the channel area of the semiconductorlayer. By applying or not applying the electric field to the channelarea in accordance with the current applied (or not applied) to the gateelectrode, the current flow can be controlled.

At this time, the length of the channel area, referred to as “channellength” or a width thereof, referred to as “channel width”, that is, thesize of the channel area is, is important to determine thecharacteristics of TFTs. Further, an arrangement of the gate electrodeon the channel area is also a very important factor. In this regard, inthe related art, a conductive member electrically connected to thescanning line or a member constituting a part of the scanning line, canbe used as the gate electrode. However, there are problems in arrangingthe scanning line itself and the channel area.

In short, it is beneficial or required to realize a suitable arrangementof the channel area (or TFT) and the scanning line (or gate electrode)while realizing the high precision required in the electro-opticaldevices. Further, it is beneficial or required to realize the difficulttask of precisely operating the TFT constructed as such.

For example, it is not sufficient to only drive the electro-opticaldevice by the TFT, and the scanning line (or the gate electrode) andvarious elements are additionally required. However, it is generallydifficult to accomplish the above arrangement or adjustment inconnection with various other elements. Further, in the TFT, there is adisadvantage if it is required to prevent the light leakage currentwhich is generated by the light entering the channel area. That is, itis preferable that the TFT is arranged as far as possible from alight-transmitting area, which is an area that the light contributes toimage display in each pixel emitted through transmission or reflection,more specifically, from the pixel electrode. However, since this shouldbe realized while satisfying the requirement of high precision, there isa further disadvantage in that the above arrangement/adjustment becomesan even more difficult task.

The present invention address the above and/or other problems, andprovides an electro-optical device capable of easily adjusting thearrangement of a gate electrode and a scanning line and capable ofprecisely driving TFT and an electronic apparatus including theelectro-optical device.

In order to address or solve the above problems, the electro-opticaldevice of the present invention includes, on a substrate, scanning linesextending in a predetermined direction, data lines extending in adirection intersecting the scanning lines, thin-film transistors formedcorrespondingly to intersecting areas of the scanning lines and the datalines, and pixel electrodes formed correspondingly to the thin-filmtransistors. The respective scanning line has a broad width portion as agate electrode in a portion facing a channel area of the respectivethin-film transistor and a narrow width portion in the other portion.

According to the electro-optical device of the present invention, bysupplying scan signals and image signals to the thin-film transistorsthrough the scanning lines and the data lines, the pixel electrodes canbe driven in an active matrix mode.

More specifically, in the present invention, since the scanning lineshave the broad width portions as the gate electrode in a portion facingthe channel area of the thin-film transistor and the narrow widthportion in other portion, it is not only possible to realize thenarrowness of the scanning line but also to more easily adjust/determinethe arrangement between the channel area (or the thin-film transistor)and the scanning line than in the related art.

For example, when a plurality of pixel electrodes are arranged in amatrix shape, it is generally preferable that the thin-film transistorare configured such that the channel area of the thin-film transistor ispositioned at the position farthest from the corner of each pixelelectrode, that is, at the center position of a space among adjacent andopposite corners of the pixel electrodes when four pixel electrodes areconsidered (because it is farthest from the light transmitting area).However, in this case, by allowing the channel area to extend through aspace between adjacent pixel electrodes including the center position,it is possible to adequately determine the channel length, and byarranging the scanning line to intersect it, it is possible to realize astructure that the broad width portion of the scanning line exists onthe channel area. Therefore, in this case, it is possible tosimultaneously realize the trade-off requirements in securing theadequate channel length, that is, securing an adequate operationcharacteristic of the thin-film transistor and the narrowness of thescanning line, required for high precision or miniaturization of theelectro-optical devices. Further, in this case, the light incidence tothe thin-film transistor or the channel area can be prevented as much aspossible or reduced under the above-described assumption.

Like the above, according to the present invention, it is possible toadequately adjust the arrangement between the thin-film transistor andthe scanning line or the gate electrode while satisfying the highprecision requirements of the electro-optical devices. Further, thisstructure renders a good outcome even after arrangement of variouselements constituting the electro-optical device has been adjusted anddetermined, in addition to the above scanning line and the thin-filmtransistor. Furthermore, according to the present invention, it ispossible to precisely drive the thin-film transistor, and thus maintainthe quality of image to be displayed at high level.

Further, in the present invention, “broad width” means that it isbroader than the width of the “narrow width portion,” and “narrow width”means that it is narrower than the width of the “broad width portion”.In short, the broad and narrow degree of “the broad width portion” andthe “narrow width portion” is determined in accordance with the relativerelationship between them. Furthermore, the real width of the broadwidth portion or the narrow width portion can be adequately determinedtheoretically, experimentally or by simulation.

In one aspect of the electro-optical device of the present invention,the broad width portion has a portion lengthened from the narrow widthportion.

According to this aspect, it is possible to form the scanning linerelatively easily having the broad width portion and the narrow widthportion. More specifically, for example, by employing known, related artor later developed photolithography and etching methods with theassumption that the broad width portion and the narrow width portion areformed through the incorporated pattern, the scanning line according tothe present aspect can be easily formed.

In another aspect of the electro-optical device of the presentinvention, the broad width portion has a portion connected to the narrowwidth portion.

According to this aspect, for example, the broad width portion includesthe portion formed by connecting a conductive member and the likeprepared separately to the narrow width portion. Even in this case, thebroad width portion can be formed relatively easily.

In another aspect of the electro-optical device of the presentinvention, the scanning line extends in a direction intersecting thedirection in which the channel area extends and the broad width portionextends in a single direction or bi-directionally in which the channelarea extends.

According to this aspect, since the broad width portion extends in thesingle direction or bi-directionally in which the channel area extends,it is possible to more adequately adjust the arrangement of thethin-film transistor and the scanning line. Further, according to thisaspect, since the gate electrode is adequately formed in accordance withthe channel length, the electric field can be more effectively appliedto the channel area.

Further, like the above, according to the aspect that the gateelectrode, that is, the broad width portion is provided in the portionto be the channel area corresponding to the channel area, for example,the so-called self-aligned formation of the thin-film transistor (thatis, formation of the source area and the drain area adjacent to thechannel area through an ion implantation process using the gateelectrode as a mask) can be easily executed. However, in this case,strictly speaking, the channel area is formed by carrying out the ionimplantation process after forming the broad width portion to be thegate electrode.

In another aspect of the electro-optical device of the presentinvention, the pixel electrodes are arranged in a matrix shape and thechannel areas are formed in an intersecting area in which a first longgap extending through a space between pixel electrodes sandwiching ofthe scanning line and being adjacent to each other and a second long gapextending through a space between pixel electrodes sandwiching the dataline and being adjacent to each other are intersected.

This aspect is similar to the above mentioned aspect and is one of theaspects in which the operational effect of the present invention isexhibited most effectively.

That is, according to this aspect, the channel area of the thin-filmtransistor is formed in the intersecting area of the pixel electrodesarranged in a matrix shape. The intersecting area is an area in whichthe first long gap extending through a space between pixel electrodessandwiching the scanning line and being adjacent to each other and thesecond long gap extending through a space between pixel electrodessandwiching the data line and being adjacent to each other areintersected in plan view. By such a configuration, it is difficult forlight to enter the channel area.

Further, along with such an operational effect, since the scanning linehas the broad width portion as the gate electrode is opposite to thechannel area, the arrangement between the channel area (or the thin-filmtransistor) and the gate electrode (or the scanning line) can bedetermined most adequately and it is also possible to secure theadequate channel length and narrowness of the scanning line.

In this aspect, in particular, the narrow width portion is formed at aposition deviated from a center of the first gap and the broad widthportion, is formed at the center of the first gap in the intersectingarea.

According to this configuration, the narrow width portion of thescanning line extends through the space between the adjacent pixelelectrodes but does not exist at the center thereof and is formed at theposition deviated from the center thereof. As a result, first, theenhancement in the quality of the displayed image can be obtained,especially for the liquid crystal display device that is an example ofthe electro-optical device, and the reason thereof is as follows.

That is, in the present aspect, when performing the rubbing process on aconvex portion on the oriented film normally provided in the liquidcrystal display device, in particular, a convex portion formed by“height” of the narrow width portion, nonuniformities are usuallygenerated in the convex portion. Further, it is considered that thedegree of nonuniformity is different from each other in the portionassociated with the rubbing up convex portion (that is, the directionascending to the convex portion) and the portion associated with therubbing down convex portion (that is, the direction descending from theconvex portion).

More specifically, for example, it is more difficult to generatenonuniformity in the portion associated with the rubbing up convexportion than in the portion associated with the rubbing down convexportion.

Further, if the nonuniformity is left as it is, a poor orientation ofthe liquid crystal may be caused to result in the operation failure ofthe electro-optical devices. In the difference in the degree ofnonuniformity between the rubbing-up process and the rubbing-downprocess, the latter has greater possibility to cause the bad orientationof the liquid crystal than the former.

It is significant that the narrow width portion of the present aspect isformed at a position deviated from the center of the first gap betweenthe pixel electrodes. That is, if the narrow width portion is formed atthe above-described position, the vertex of the convex portion caused bythe narrow width portion is also formed at the position deviated fromthe center of the first gap, and this means that it is possible to formalmost only half inclined surface of the convex portion on the areacorresponding to the first gap, that is, to form only the portionassociated with the rubbing-down on the area. Further, in this case, ifthe light-shielding film is provided corresponding to the first gap, itis possible to effectively shield only the portion associated with therubbing-down, that is, to effectively shield the corresponding portionof the convex portion to be most influenced by the nonuniformity.

As a result, according to the present aspect, since the operationfailure of the electro-optical device caused by nonuniformities can besubstantially prevented or reduced, and the portion of the convexportion associated with the rubbing-up, which is not affected bynonuniformities, is able to transmit the light contributing to the imagedisplay. Thus, it is possible to enhance the opening ratio of pixel,that is, to provide a brightened image display. As a result, accordingto the present aspect, from the above-mentioned point of view, theenhancement in the display image can be obtained.

Further, by forming the narrow width portion at the position deviatedfrom the center of the first gap, it is also possible to enhance thedegree of freedom in designing the electro-optical devices and to moreeffectively prevent or reduce light from entering the thin-filmtransistor. The reason thereof is as follows.

That is, in the present aspect, the narrow width portion extends throughthe first gap between the adjacent pixel electrodes, but does not existat the center thereof. For this reason, by using the area in the firstgap where the narrow width portion is not provided, in a plan view, itis possible to provide other wires, such as the capacitive line made upof the same film as the narrow width portion, in parallel to the narrowwidth portion. That is, the degree of freedom of design is increased.

Further, in the above-mentioned case, although the narrow width portionis deviated from the center thereof, it is possible to arrange the broadwidth portion as the gate electrode at the center of the gap, byadjusting the width of the broad width portion, for example, bybroadening only one side or by broadening one side more than the othersmall side. Like the above, since the gate electrode can be arranged ata position advantageous to increase the light-shielding abilityregardless of the position of the scanning line, or since the scanningline can be arranged at an arbitrary portion in the gap while arrangingthe gate electrode at the position advantageous for increasing thelight-shielding ability, it is possible to realize a thin-filmtransistor having a high light-shielding ability while increasing thedegree of freedom in arranging wires including the arrangement of thescanning lines.

In this configuration, further, the broad width portion may be formed atthe center of the second gap in the intersecting area.

According to such construction, the channel area is formed at theposition farthest from the adjacent or opposite corners of theelectrodes in accordance with the above-described method, when fourpixel electrodes are considered to be used. That is, it becomes verydifficult for light to enter the channel area.

In another aspect of the electro-optical device of the presentinvention, grooves are formed in the substrate along the scanning lines,and the scanning lines are buried at least partially in the groovesdirectly or through an interlayer insulating film.

According to this aspect, since the scanning line is buried in thegroove formed in the substrate, the generation of a step on the surfaceof the interlayer insulating film formed as the upper layer or on thesurface of the pixel electrodes and the oriented film, etc. caused bythe height of the scanning line itself can be prevented or reducedearlier. That is, the surface can be leveled very well. Then, if thesurface of the oriented film is leveled, the rubbing process can beadequately performed for the orientation process and the orientatedstate of the liquid crystal molecules contacting the oriented film canbe maintained well. Therefore, according to the present aspect, sincethe possibility of bad orientation can be decreased and the lightleakage caused by the bad orientation can be markedly prevented orreduced, it is possible to display a high-quality image.

In another aspect of the electro-optical device of the presentinvention, the narrow width portion has a buried portion buried in thegroove and extending along the scanning line and a non-buried portionnot buried in the groove and extending along the scanning line inparallel to a buried portion, and a base of the pixel electrode ispositioned high along the scanning line due to the presence of thenon-buried portion.

According to this aspect, the narrow width portion has both the buriedportion and the non-buried portion. Then, both of the buried portion andthe non-buried portion extend along the scanning line and the base ofthe pixel electrode protrudes above along the scanning line due to thepresence of the non-buried portion.

Through this construction, first, the effect associated with theabove-described leveling can be similarly obtained by the buriedportion. That is, the surface of the interlayer insulating film to beformed as the upper layer of the buried portion, or the surfaces of thepixel electrodes and the oriented film have the an excellent leveledfeature, and thus it is possible to reduce the possibility of having thebad orientations.

Next, since the step including the convex portion along the scanningline is formed on the surface of the oriented film to be formed as theupper layer of the non-buried portion and the like, the above-describedeffects of leveling cannot be obtained by the non-buried portion.However, the following advantages can be obtained.

First, in electro-optical device according to the present invention, forthe purpose of preventing or reducing deterioration of the liquidcrystal, increasing the device life and reducing the cross-talk orflicker of the displayed image, a method of dividing the pixelelectrodes into two groups and then inversely driving them in separatecycles may be employed. That is, a plurality of pixel electrodesincluding a first pixel electrode group to be inversely driven at afirst period and a second pixel electrode group to be inversely drivenat a second period compensatory with the first period, are arranged in aplain on the substrate. There are (i) the adjacent pixel electrodes tobe driven with driving voltages of inverse polarities at the respectivetimes in the inverse-driving, and (ii) the adjacent pixel electrodes tobe driven with driving voltages of the same polarity at the respectivetimes in the inverse driving. If the pixel electrodes corresponding to(i) are arranged in the direction along the data lines and the pixelelectrodes corresponding to (ii) are arranged in the direction along thescanning lines, the pixel electrodes arranged in the direction along anyone scanning line are driven with one polarity and the pixel electrodesarranged in the direction along another scanning line adjacent to theany one scanning line are driven with an inverse polarity to the onepolarity (referred to as “1H inverse driving”).

However, in this case, between the pixel electrodes adjacent to eachother along the data line, the horizontal electric field based on thedriving voltages of inverse polarities is generated. Such horizontalelectric field may interfere the electric field (may be referred to asvertical electric field in contrast to the horizontal electric field)generated between the pixel electrode and the opposing electrode, and asa result, it becomes difficult to obtain the orientation state of theliquid crystal molecules as desired, so that the image display may beaffected.

Further, in the present aspect, in a case that such adverse effects maybe caused, the convex portion formed on the base of the pixel electrodealong the scanning line has a distinct significance.

That is, first, when the edge portions of the respective pixelelectrodes are formed to be positioned on the step, the verticalelectric field generated between the respective pixel electrodes and theopposing electrode is intensified compared to the horizontal electricfield generated between the adjacent pixel electrodes (in particular,the pixel electrodes included in the different pixel electrode group).That is, since the electric field generally intensifies as the distancebetween the electrodes becomes shorter, the edge portions of the pixelelectrodes near the opposing electrode by the height of the stepgenerates an intense vertical electric field. Second, whether the edgeportions of the respective pixel electrodes are positioned on the stepor not, the horizontal electric field generated between the adjacentpixel electrodes (in particular, the pixel electrodes included in adifferent pixel electrode group) is weakened by the presence of the stepin accordance with the dielectric constant, and even by reducing(replacing partially from the step) the volume of the electro-opticalmaterial through which the horizontal electric field passes, the effectthat the horizontal electric field has on the electro-optical materialcan be reduced. Therefore, the operation failure from theelectro-optical material, such as the bad orientation of the liquidcrystal by the horizontal electric field caused by the inverse drivingmethod, can be reduced. At this time, as described above, the edgeportions of the pixel electrodes may be or not be positioned on the stepand may be positioned on the inclined step or on an almost vertical sidesurface thereof.

In addition, since the light-shielding film to conceal the operationfailure caused by the electro-optical material, can be formed small, itis also possible to increase the opening ratios of the respective pixelswithout having the bad image display, caused by the light leakage,generated.

As described above, according to the present aspect, first, due to thepresence of the buried portion, the effects associated with theabove-described leveling can be obtained, and second, by formingintentionally the step including the convex portion along the scanningline by the presence of the non-buried portion, the generation of thehorizontal electric field can be prevented or reduced.

In another aspect of the electro-optical device of the presentinvention, a capacitor electrode on a pixel potential side constitutinga storage capacitor connected to the pixel electrode and a capacitiveline having capacitor electrode on a fixed potential side arrangedconstituting the storage capacitor arranged opposing the capacitorelectrode on the pixel potential side through a dielectric film, may befurther provided. The capacitive line has a main line portion extendingalong the scanning line and a portion extending along the data line, anda width of the portion extending along the data line in the capacitiveline is equal to or broader than that of the data line.

According to this aspect, since the storage capacitor, having aconstruction such that the capacitor electrode on the pixel potentialside and the capacitor electrode on the fixed potential side arearranged opposite to each other, is connected to the pixel electrode,the voltage of the image signal written in the pixel electrode can bemaintained for a long time. In particular, in the present aspect, sincethe width of the portion extending along the data line in the capacitiveline is equal to or broader than that of the data line, it is possibleto further lower the resistance of the capacitive line. Further, in thepresent aspect, since a low resistance of the capacitive line can berealized as described above, from the point of view of the whole device,the narrowness of the capacitive line and further narrowness of thestorage capacitor can be accomplished, and as a result, it is possibleto enhance the opening ratio. In the “narrowness of the capacitiveline”, since the capacitive line itself has a width equal to or “broaderthan” the width of the data line on the surface, it may appear to be acontradiction, but the broad width and the narrow width should bedetermined from the relative relationship between the capacitive lineand the data line, such that from the point of view of the whole device,the “narrowness of the capacitive line” can be accomplished, compared tothe related art. Furthermore, in the broad width and narrow widthdescribed above or the “broader than” to be described in the presentinvention, the discrete values of the width can be adequately determinedtheoretically, experimentally, experientially or by simulation.

Further, according to the present aspect, it is possible to effectivelyprevent or reduce the light from entering the thin-film transistor, inparticular the channel area thereof, compared to the related art, aswell as obtaining the above-described low resistance. This is because,as described above, although in the conventional art, the lightreflected from the back of the data line and the like becomes a straylight and thus may enter the thin-film transistor, but according to thepresent aspect, the possibility that the advance of such stray light isshielded by the capacitive line formed in the width equal to or broaderthan that of the data line is increased.

From the above, according to the present invention, the problems, suchas the cross-talk or burn-in that were prevalent in the related art, canbe reduced by the low resistance of the capacitive line. Further, sincethe light leak current in the thin-film transistor is reduced, it ispossible to display a high quality image.

Further, in the present invention, since the portion extending along thedata line exists in the capacitive line, the area of the storagecapacitor can be increased. This markedly contributes to the imagedisplay having high quality.

Furthermore, in order to more effectively accomplish the light-shieldingfunction described above, materials having a good light-shieldingfeature may be employed for the capacitive line. For example, singlemetal, alloy, metal silicide, poly-silicide or laminated layer thereof,containing at least one from Al (aluminum), Cu (copper), Ti (titan), Cr(chrome), W (tungsten), Ta (tantalum), and Mo (molybdenum) can beadequately employed. Further, in addition to the above, for example,light-absorbing materials such as poly-silicon can be employed.

In this aspect, a portion overlapping the thin-film transistor in thedata line may be formed locally broad, and a width of the portionextending along the data line in the capacitive line may be broader thanthat of the portion not formed broad in the data line and equal to thatof the portion formed broad in the data line.

By such a construction, the portion overlapping the thin-film transistorin the data line is formed locally broad. Then, the width of the portionformed broad is equal to that of the portion extending along the dataline in the above-described capacitive line. That is, from thisconstruction, the data line and the capacitive line all formed broad arepositioned on the thin-film transistor. Thus, the light entered from theupper portion of the thin-film transistor can be more securely preventedor reduced.

More specifically, for example, when the capacitive line is made up ofmetal having a high melting point, the capacitive line can independentlyhave the light-shielding ability that the transmittance thereof is about0.1% (2 or more in OD (Optical Density)). However, if the silicideforming process is performed on the capacitive line, the compositionthereof is varied and thus the light-shielding ability may be reduced.In this case, only the light-shielding ability having the transmittanceof 0.1% or more may be obtained.

However, in the present aspect, the data line overlapping the capacitiveline formed of such a metal film having a high melting point is furtherprovided. If the construction for performing the light shielding of thethin-film transistor by overlapping the capacitive line and the dataline is employed, the light-shielding ability corresponding to the addedvalue of these transmittances can be obtained. For example, when thedata line is made up of aluminum, etc., the light-shielding ability witha transmittance of 0.001% or less (4 or more in the OD value) can beaccomplished.

Further, in the present aspect, in particular, that the broad width ofthe portion extending along the data line in the capacitive line isbroad means that it is broader than that of the portion not formed broadin the data line.

Also, a portion overlapping the thin-film transistor in the data line isformed locally broad, and a width of the portion extending along thedata line in the capacitive line is broader than that of the portion notformed broad in the data line and narrower than that of the portionformed broad in the data line.

According to this aspect, the portion overlapping the thin-filmtransistor in the data line is formed locally broad. That is, from thisconstruction, the data line and the capacitive line all formed broad arepositioned on the thin-film transistor. Therefore, the light enteredfrom the upper portion of the thin-film transistor can be more securelyprevented or reduced.

Furthermore, in the present aspect, in particular, the width of theportion extending along the data line in the capacitive line is formednarrower than that of the data line. That is, in the portion, the widthof the data line is narrower than that of the capacitive line. From thisconstruction, for example, when the data line is made up of aluminumhaving a high light reflexibility, a stray light generated by reflectingthe incident light by any element in the electro-optical device, a lightreturning to the electro-optical device after a light emitted from theelectro-optical device is reflected by any element outside of theelectro-optical device, or in a projection type display device, such asa color-displayable liquid crystal projector including a plurality ofelectro-optical devices, a light emitted from other electro-opticaldevice and generated by returning to the electro-optical device isreflected by the data line to thereby prevent the stray light from beingincreased. This is because the portion of the data line formed broad isrelatively narrower than the capacitive line.

In this aspect that has the data line having a portion overlapping thethin-film transistor formed broad, the capacitive line is arranged atthe overlapped position between the thin-film transistor and the dataline, and the data line may be constructed such that the portionprovided with a contact hole to connect to the thin-film transistor isformed broad in addition to the portion overlapping the thin-filmtransistor.

From this construction, even when the capacitive line as thelight-shielding film could is not provided, the decrease in thelight-shielding ability can be compensated by forming broad the dataline for the contact hole.

Alternatively, for each thin-film transistor, the data line is formedcontinuously broad from the portion overlapping the thin-film transistorto the portion in which the contact hole is provided.

From this construction, the light shielding of the thin-film transistorcan be more securely accomplished.

Further, the portion formed broad in the portion overlapping thethin-film transistor and the portion formed broad in the portion inwhich the contact hole is provided may be separately formed broad. Ifarranging the portion overlapping the thin-film transistor and theportion in which the contact hole is provided close to each other andforming them continuously broad as in the present aspect, since the areato be formed broad need not be exceedingly broad, it is advantageousfrom the point of view of not increasing the inner reflection.

In another aspect of the electro-optical device of the presentinvention, another substrate opposing the substrate through anelectro-optical material and a light shielding film formed on theanother substrate may be further provided, and the width of the dataline and the width of a portion extending along the data line in thecapacitive line are narrower than that of the light-shielding film.

From this aspect, if it is assumed that the light is entered fromanother substrate, the laminated structure of the light-shielding film,the data line and the capacitive line in the order from the lightincidence side can be constructed. The width of the former is broaderthan those of the latter two. That is, the advance of the incident lightis blocked by the broader light-shielding film, and only the lightpassing through it reaches the data line and the capacitive line.Further, when the light passing through the light-shielding film reachesthe data line and the capacitive line, the data line and the capacitiveline can be expected to perform the above-described light-shieldingfunction. In short, according to the present aspect, it is possible toenhance the light resistance of the thin-film transistor and to reducethe generation of the light leakage.

Further, if the pixel electrodes are arranged in a matrix shape, the“light-shielding film” in the present aspect may be formed in a stripeshape or a lattice shape to extend through spaces between the pixelelectrodes. Furthermore, according to circumstances, the light-shieldingfilm may be formed as a laminated structure made of, for example, alight-absorbing material, such as chrome or chrome oxide, and alight-reflecting material, such as aluminum.

An electronic apparatus of the present invention may include theabove-described electro-optical device (including various aspects).

According to the electronic apparatus of the present invention, forexample, since it includes the electro-optical device capable ofadequately adjusting the arrangement between the thin-film transistorand the scanning line, it is possible to realize various electronicapparatuses, such as a liquid crystal projector, a liquid crystaltelevision, a portable phone, an electronic pocket book, a wordprocessor, a view finder type or monitor direct vision-type videotaperecorder, a work station, a video phone, a POS terminal, and a touchpanel, capable of precise operation of the thin-film transistor and highquality image display, for example.

The above effects and other advantages of the present invention will bemore apparent from the following exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic circuit diagram illustrating an equivalent circuitof various elements, wirings and the like provided in a plurality ofpixels, having a matrix shape, constituting an image display area in anelectro-optical device according to an exemplary embodiment of thepresent invention;

FIG. 2 is a plan view of a group of adjacent pixels in a TFT arraysubstrate where data lines, scanning lines, pixel electrodes are formedin the electro-optical device according to an exemplary embodiment ofthe present invention;

FIG. 3 is a sectional view taken along plane A–A′ in FIG. 2;

FIG. 4 is a plan view illustrating only a shape pattern of the scanninglines shown in FIG. 2;

FIG. 5 is a plan view illustrating another exemplary embodiment in whichthe arrangement of the scanning lines and the TFTs is different fromthat in FIG. 2;

FIG. 6 is a plan view illustrating only a shape pattern of the scanninglines shown in FIG. 5;

FIG. 7 is a sectional view taken along plane B–B′ in FIG. 5;

FIG. 8 is a plan view illustrating another exemplary embodimentdifferent from that in FIG. 2 in that grooves are formed on the TFTarray substrate and the scanning lines are buried in the grooves;

FIG. 9 is a sectional view illustrating a profile of a narrow widthportion of the scanning lines shown in FIG. 8;

FIG. 10 is a plan view illustrating another exemplary embodimentdifferent from that in FIG. 2 in that grooves are formed on the TFTarray substrate and a part of the scanning lines are buried in thegrooves;

FIG. 11 is a sectional view illustrating a profile of a narrow widthportion of the scanning line shown in FIG. 10;

FIG. 12 is a sectional view taken along plane T–T′ in FIG. 10;

FIGS. 13( a) and 13(b) are schematics explaining the generation of ahorizontal electric field;

FIG. 14 is a plan view illustrating another exemplary embodimentdifferent from that in FIG. 2 in that grooves are formed on the TFTarray substrate and the narrow width portion of the scanning line isdeviated from the center of a first gap;

FIG. 15 is a sectional view taken along plane T–T′ in FIG. 14;

FIG. 16 is a plan view illustrating another exemplary embodiment in thata shape of the data line is different from that in FIG. 2;

FIG. 17 is a sectional view taken along plane P–P′ in FIG. 16;

FIG. 18 is a sectional view taken along plane Q–Q′ in FIG. 16;

FIG. 19 is a sectional view taken along plane R–R′ in FIG. 16;

FIG. 20 is a plan view where the TFT array substrate of theelectro-optical device according to the exemplary embodiment of thepresent invention is viewed from the opposing substrate side along withthe respective elements formed thereon;

FIG. 21 is a sectional view taken along plane H–H′ in FIG. 20;

FIG. 22 is a schematic sectional view illustrating a color liquidcrystal projector that is an example of a projection type color displayapparatus as an exemplary embodiment of an electronic apparatus of thepresent invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred exemplary embodiments of the present invention are explainedwith reference to the drawings. In following exemplary embodiments, anelectro-optical device of the present invention is applied to a liquidcrystal device.

First, a construction of a pixel part in the electro-optical deviceaccording to an exemplary embodiment of the present invention isexplained with reference to FIGS. 1 to 4. FIG. 1 is a schematic thatshows an equivalent circuit of various elements, wirings and the like ina plurality of pixels formed in a matrix shape constituting an imagedisplay area 10 a of the electro-optical device. FIG. 2 is a plan viewof a group of a plurality of pixels adjacent to each other on a TFTarray substrate in which data lines, scanning lines, pixel electrodesand the like are formed. Further, FIG. 3 is a sectional view taken alongplane A–A′ in FIG. 2. Further, in FIG. 3, in order for each layer andeach member to have recognizable sizes in the drawing, different scalesare applied to each layer and each member. Furthermore, FIG. 4 is a planview illustrating shapes of only the scanning lines extracted from FIG.2.

In FIG. 1, in the plurality of pixels formed in a matrix shapeconstituting the image display area of the electro-optical deviceaccording to the present exemplary embodiment, a pixel electrode 9 a anda TFT 30 to control switching of the pixel electrode 9 a are formed,respectively, and data lines 6 a supplied with image signals areelectrically connected to sources of the TFTs 30. Image signals S1, S2,. . . , Sn to be, in this order, written may be sequentially supplied tothe data lines 6 a, or may be supplied to each group which has aplurality of data lines 6 a adjacent to each other.

Further, scanning lines 330 a are electrically connected to gates of theTFTs 30 and at a predetermined timing, scanning signals G1, G2, . . . ,Gn are pulse-like applied to the scanning lines 330 a in that order. Thepixel electrodes 9 a are electrically connected to drains of the TFTs30, and by closing switches of the TFTs 30, that is, switching elementsfor a predetermined time interval, the image signals S1, S2, . . . , Snsupplied from the data lines 6 a are written at a predetermined timing.

A predetermined level of the image signals S1, S2, . . . , Sn which havebeen written through the pixel electrodes 9 a to a liquid crystal thatis an example of an electro-optical material are maintained for apredetermined time interval between the pixel electrode 9 a and anopposing electrode formed on an opposing substrate. The liquid crystalmodulates light by varying orientation or order of molecules accordingto the applied voltage level, and thus it is possible to execute thegradation display. If it is in a normally-white mode, transmittance forthe incident light is decreased in accordance with the voltage appliedin a unit of pixel, and if it is in a normally-black mode, thetransmittance for the incident light is increased in accordance with thevoltage applied in a unit of pixel. Therefore, as a whole, light havinga contrast responsive to the image signals is emitted from theelectro-optical device.

In order to reduce or prevent the maintained image signals from beingleaked, a storage capacitor 70 is added in parallel to a liquid crystalcapacitor formed between the pixel electrode 9 a and the opposingelectrode.

A more specific construction of the electro-optical device in which theabove-described circuit operation is executed by using the data lines 6a, the scanning lines 330 a, the TFTs 30 and the like is explained withreference to FIGS. 2 and 3.

First, the electro-optical device according to the present exemplaryembodiment, as shown in FIG. 3 which is a sectional view taken alongplane A–A′ in FIG. 2, includes a TFT array substrate 10 and atransparent opposing substrate 20 arranged opposite thereto. The TFTarray substrate 10 is made of, for example, a quartz substrate, a glasssubstrate or a silicon substrate, and the opposing substrate 20 is madeof, for example, a glass substrate or a quartz substrate.

As shown in FIG. 3, the TFT array substrate 10 is provided with a pixelelectrode 9 a, and an upper portion of the pixel electrode is providedwith an oriented film 16 which has been subjected to a predeterminedorientation process, such as a rubbing process. The pixel electrode 9 ais made of, for example, a transparent conductive film, such as an ITO(Indium Tin Oxide) film.

The opposing substrate 20 is provided over the whole surface thereofwith an opposing electrode 21, and a lower portion of the electrode isprovided with an oriented film 22 which has been subjected to apredetermined orientation process, such as a rubbing process. Theopposing electrode 21 is made of, for example, a transparent film, suchas an ITO film.

Next, in FIG. 2, a plurality of pixel electrodes 9 a (profiles thereofare indicated by dotted lines 9 a′) are provided in a matrix shape onthe TFT array substrate 10 of the electro-optical device, and data lines6 a of aluminum films and scanning lines 330 a of poly-silicon films areprovided along horizontal and vertical boundaries of the pixelelectrodes 9 a.

Each scanning line 330 a is arranged opposite to a channel area 1 a′indicated by oblique lines area extending from lower left to upper rightin the semiconductor layer 1 a of a poly-silicon film and functions as agate electrode. That is, in portions where the scanning lines 330 a andthe data lines 6 a are intersected, TFTs 30 to switch pixels where broadwidth portions 331 a (to be explained later) of the scanning lines 330 aare arranged opposite to the channel areas 1 a′ as gate electrodes areprovided. In other words, TFTs 30 in the present exemplary embodiment,in particular, the channel areas 1 a′ thereof are formed in intersectingareas of the plurality of pixel electrodes 9 a arranged in a matrixshape. The intersecting area means an area where, in plan view, a firstlong gap (X direction in FIG. 2) extending through a space betweenadjacent pixel electrodes 9 a sandwiching the scanning linestherebetween and a second long gap (Y direction in FIG. 2) extendingthrough a space between adjacent pixel electrodes sandwiching the dataline 6 a therebetween, are intersected.

More specifically, with reference to FIG. 2, the intersecting areacorresponds to, for example, a position farthest from each of alower-right corner of the pixel electrode 9 a shown on the upper-leftside of the plan view, a lower-left corner of the pixel electrode 9 ashown on the upper-right side, an upper-right corner of the pixelelectrode 9 a shown on the lower-left side and an upper-left corner ofthe pixel electrode 9 a shown on the lower-right side of the plan view.Since the TFT 30 is formed at such position, it is difficult for anincident light to directly enter the channel area 1 a′ of the TFT.

The TFT 30, as shown in FIG. 3, has an LDD (Lightly Doped Drain)structure, and includes a channel area 1 a′ of the semiconductor layer 1a where a channel is formed by an electric field from the scanning linewhich functions as a gate electrode as described above, an insulatingfilm 2 having a gate insulating film to insulate the scanning line 330 afrom the semiconductor layer 1 a, a low-concentration source area 1 b, alow-concentration drain area 1 c, a high-concentration source area 1 dand a high-concentration drain area 1 e.

Further, although it is preferable that the TFT 30 has the LDD structureas shown in FIG. 3, the TFT 30 may have an offset structure in whichimpurities are prevented or substantially prevented from beinginfiltrated into the low-concentration source area 1 b and thelow-concentration drain area 1 c, or may be a self-alignment type TFT toinfiltrate impurities at high concentration using the gate electrodeconstituting a part of the scanning line 330 a as a mask toautomatically form the high-concentration source area and thehigh-concentration drain area. Furthermore, although, in the presentexemplary embodiment, the TFT 30 has a single gate structure where onlyone gate electrode of the TFT 30 for pixel switching is disposed betweenthe high-concentration source area 1 d and the high-concentration drainarea 1 e, the TFT may have a dual, triple or more gate structure wheretwo or more gates are disposed therebetween. Furthermore, thesemiconductor layer 1 a constituting the TFT 30 is not limited to thepoly-silicon film, but may be made of an amorphous silicon film or amonocrystalline silicon film. A related art, later developed, or knownmethod, such as a pasting method can be employed in formation of themonocrystalline silicon film. By employing the monocrystalline siliconfilm for the semiconductor layer 1 a, it is possible to promote a highperformance of the peripheral circuits.

In the present exemplary embodiment, for the scanning line 330 a servingas the gate electrode of the TFT 30, a portion serving as the gateelectrode, that is, a portion facing the channel area 1 a′ of the TFT 30is formed broader than the other portion, as shown in FIG. 2. That is,in FIG. 2, the scanning line 330 a has a broad width portion 331 aextending in the Y direction in FIG. 2 to correspond to the channel area1 a′ extending in the Y direction in FIG. 2 and a narrow width portion332 a extending through a space between the adjacent pixel electrodes 9a. In FIG. 4, for the purpose of simplifying the illustration, only theshape pattern of the scanning line 330 a is shown.

In this connection, in the present exemplary embodiment, the broad widthportion 331 a is lengthened from the narrow width portion 332 a. Thatis, the broad width portion 331 a and the narrow width portion 332 a areintegrally formed. Such a shape can be easily formed, for example, byusing a related art, later developed, or known photolithography andetching, on the assumption that a pattern having an integrated shape 332a (see FIG. 4) composed of the broad width portion 331 a and the narrowwidth portion 332 a is formed. However, the present invention is notlimited to such shape, and includes, for example, even shapes where thebroad width portion 331 a is formed by connecting other conductivemember prepared separately to the narrow width portion 332 a, within thescope thereof.

The storage capacitor 70 shown in FIG. 1 is constructed such that ajunction layer 71 as the capacitor electrode on the pixel potential sideconnected to the high-concentration drain area 1 e of the TFT 30 and thepixel electrode 9 a and a part of the capacitive line 300 as thecapacitor electrode on the fixed potential side are arranged opposite toeach other via an dielectric film 75, as shown in FIG. 3. By the storagecapacitor 70, it is possible to markedly enhance the potentialmaintenance characteristics in the pixel electrode 9 a.

The junction layer 71 is made up of, for example, the conductivepoly-silicon film and serves as a capacitor electrode on the pixelpotential side. However, similar to the capacitive line 300 to beexplained in detail below, the junction layer 71 may be made of a singlelayer film or multi-layer film containing metal or alloy. In addition tothe function as a capacitor electrode on the pixel potential side, thejunction layer 71 also has a function of connecting the pixel electrode9 a and the high-concentration drain area 1 e of the TFT 30 to eachother through contact holes 83 and 85.

By using such junction layer 71, even if the distance between layers isas long as, for example, 2000 nm, both layers can be connected well toeach other through serial contact holes having two relatively smalldiameters while avoiding the technical difficulty of connecting bothlayers to each other through one contact hole, so that an opening ratioof pixel can be increased. Further, in opening the contact hole, it ishelpful to prevent or reduce punchthrough in etching.

The capacitive line 300 is made of for example, a conductive filmcontaining metal or alloy, and serves as a capacitor electrode on thefixed potential side. The capacitive line 300 is formed overlapping anarea to form the scanning line 330 a from a plan view, as shown in FIG.2. More specifically, the capacitive line 300 has a main line portionextending along the scanning line 330 a, a protruding portion protrudedupwardly in the Y direction along the data line 6 a from a portionintersecting the data line 6 a and a constricted portion where theportion corresponding to the contact hole 85 is slightly constricted.The protruding portion contributes to increase in the area to form thestorage capacitor 70 by using the area on the scanning line 330 a andthe area below the data line 6 a.

Further, the capacitive line 300 is made of, for example, single metal,alloy, metal silicide, poly-silicide or laminated layer thereof,containing at least one of metals having high melting point, such as Ti,Cr, W, Ta, Mo, and in addition to the function as a capacitor electrodeon the fixed potential side of the storage capacitor 70, the capacitiveline 300 has a function as a light-shielding layer to shield the TFT 30from the incident light on the upper side of the TFT 30. However, thecapacitive line 300 may have a multi-layer structure in which a firstfilm made of a conductive poly-silicon film and the like and a secondfilm made of a metal silicide film containing metal and the like havinghigh melting point are stacked.

Furthermore, preferably, the capacitive line 300 extends from the imagedisplay area in which the pixel electrodes 9 a are arranged toperipheries thereof, and is electrically connected to a potentiostaticsource to be a fixed potential. Such potentiostatic source may be apotentiostatic source, such as a plus power source or a minus powersource supplied to a data line driving circuit to be explained later, ormay be a potentiostatic source supplied to the opposing electrode 21 ofthe opposing substrate 20.

A dielectric film 75, as shown in FIG. 3, is constructed of a siliconoxide film such as a HTO (High Temperature Oxide) film or a LTO (LowTemperature Oxide) film having, for example, a relatively thin thicknessof about 5˜200 nm, or a silicon nitride film. From the point of view ofincreasing the capacitance of the storage capacitor 70, the dielectricfilm 75 should be preferably as thin as possible as long as thereliability of the film is sufficiently maintained.

In FIGS. 2 and 3, in addition, the lower side of the TFT 30 is providedwith a lower light-shielding film 11 a. The lower light-shielding film11 a is patterned in a lattice shape, and as a result, the opening areaof each pixel is defined. Further, the opening area may be defined bythe intersection of the data line 6 a extending in the Y direction inFIG. 2 and the capacitive line 300 extending in the X direction in FIG.2. Furthermore, similar to the case of the above-described capacitiveline 300, the lower light-shielding film 11 a may be formed extendingfrom the image display area to the peripheries thereof to be connectedto a potentiostatic source so that the potential variation has noadverse effects on the TFT 30.

Further, a base insulating film 12 is provided below the TFT 30. Inaddition to the function of insulating the TFT 30 from the lowerlight-shielding film 11 a, since the base insulating film 12 is formedon the whole surface of the TFT array substrate 10, the base insulatingfilm 12 has a function of preventing or reducing the characteristicvariation of the TFT 30 for pixel switching caused by rough polishedsurface of the TFT array substrate 10 or contaminants left afterwashing.

In addition, a first interlayer insulating film 41 which has a contacthole 81 communicating with the high-concentration source area 1 d and acontact hole 83 communicating with the high-concentrating drain area 1e, respectively, is formed on the scanning line 330 a.

The junction layer 71 and the capacitive line 300 are formed on thefirst interlayer insulating film 41, and a second interlayer insulatingfilm 42 which has a contact hole 81 communicating with thehigh-concentration source area 1 d and a contact hole 85 communicatingwith the junction layer 71 are formed respectively on the junction layer71 and the capacitive line 300.

Furthermore, in the present exemplary embodiment, by baking the firstinterlayer insulating film 41 at about 1000° C., activation of ionsinjected into the poly-silicon film constituting the semiconductor layer1 a or the scanning line 330 a may be intended. On the other hand, bynot baking the second interlayer insulating film 42, relief of stressoccurring in the vicinity of the interface of the capacitive line 300may be intended.

The data line 6 a is formed on the second interlayer insulating film 42,and above them a third interlayer insulating film 43 which has a contacthole 85 communicating the junction layer 71 is formed.

The surface of the third interlayer insulating film 43 is leveled bymeans of CMP (Chemical Mechanical Polishing) process, and as a result,the orientation failure of the liquid crystal layer 50 caused by a stepgenerated by various wirings or elements below the third interlayerinsulating layer 73 can be reduced.

However, in place of performing the leveling process for the thirdinterlayer insulating film 43, or in addition to it, a groove, in atleast one of the TFT array substrate 10, the base insulating film 12,the first interlayer insulating film 41 or the second interlayerinsulating film 42, can be formed to buried the wirings, such as thedata line 6 a or the TFT 30 to perform the leveling process.

According to the electro-optical device of the present exemplaryembodiment as constructed like the above, since the scanning line 330 ahas the broad width portion 331 a and the narrow width portion 332 a andthe broad width portion 331 a is formed to face the channel area 1 a′ ofthe TFT 30, the arrangement between the TFT 30 and the scanning line 330a can be easily adjusted or determined.

For example, the arrangement between the TFTs 30 and the scanning lines330 a in FIG. 2 described above shows an example of a suitablearrangement responsive to the requirement to effectively prevent orsubstantially prevent light from entering the channel areas 1 a′ of theTFTs 30. In addition, for example, the arrangements shown in FIGS. 5 and6 can be implemented. FIG. 5 is a diagram with the same purpose as FIG.2, in which an arrangement of the scanning lines and the TFTs isdifferent from that in FIG. 2, and FIG. 6 illustrates only a shapepattern of the scanning lines shown in FIG. 5, similar to FIG. 4.

In FIGS. 5 and 6, the scanning lines 330 a′, more specifically, thenarrow width portions 332 a′ are formed at positions deviated from thecenter of a first long gap extending through a space between theadjacent pixel electrodes 9 a sandwiching the scanning lines 330 a′therebetween. Further, the broad width portions 331 a′ are formed to beprotruded only upwardly in the Y direction in FIGS. 5 and 6.Furthermore, the arranged positions of the channel areas 1 a′, that is,the arranged positions of the broad width portion 331 a′ are similar tothose in FIG. 2.

This arrangement can enhance the quality of display image. The reasonthereof is as follows. That is, in the electro-optical device accordingto the present invention, as described above, the oriented film 16 isprovided on the pixel electrodes 9 a, and on the surface of the orientedfilm 16, unevenness due to the “height” of various elements formed belowthe oriented film 16 can exist. The above-described “various elements”include the scanning lines 330 a′ of the present exemplary embodiment.FIG. 7 is a sectional view taken along plane B–B′ in FIG. 5, in which aconvex portion 501 caused by the “height” of the narrow width portion332 a′ of the scanning line 330 a′ is formed on the oriented film 16.

When the convex portion 501 is generated, there is a possibility offurther generating nonuniformity in the above-described rubbing processperformed on the oriented film 16. This nonuniformity may cause the badorientation of the liquid crystal and thus the operation failure of theelectro-optical device. Therefore, in the related art, by providing thelight-shielding film in the vicinity of the above-described convexportion 501, shielding of the incident light is made possible. That is,the incident light reaching the light-shielding film is reflected orabsorbed by the light-shielding film and thus does not contribute to theimage display.

At this time, it is important that the above-described light-shieldingfilm should be provided while satisfying the requirements to enhance thepixel opening ratio. That is, when the light-shielding film is providedonly to correspond to the convex portion 501, it may unnecessarilyworsen the pixel opening ratio to deteriorate the brightness of image.When the light-shielding film is provided only in a part of the convexportion 501, sufficient light-shielding cannot be accomplished and maycause the deterioration of the contrast ratio. In addition, theinfluence of the nonuniformity in the convex portion 501 may lead to theoperation failure of the electro-optical device.

In the present exemplary embodiment, it has been paid attention to thefact that the nonuniformity are generated in the convex portion 501,more specifically, that the portion (hereinafter, “rubbing-up portion501 a” in FIG. 7) associated with rubbing up the convex portion 501(that is, the direction ascending the convex portion 501) and theportion (hereinafter “rubbing-down portion 501 b” in FIG. 7) associatedwith rubbing down the convex portion 501 (that is, the directiondescending the convex portion 501), have nonuniformity different fromeach other.

More specifically, for example, it has been paid attention to the factthat it is more difficult to generate the nonuniformity in therubbing-up portion 501 a than in the rubbing-down portion 501 b, thatis, the rubbing-down portion 501 b has the higher possibility of causingthe bad orientation of the liquid crystal.

In the present exemplary embodiment, it is important that the narrowwidth portions 332 a′ adjacent in the direction of the scanning lines330 a′ in FIG. 5 are formed at the position deviated from the center(see the two-dotted chain line in FIG. 7) between the pixel electrodes 9a. That is, by forming the narrow width portion 332 a′ at the positionshown in FIG. 7, a vertex 501P of the convex portion 501 caused by thenarrow width portion 332 a′ is also formed at the position deviated fromthe center between the adjacent pixel electrodes 9 a. This means that itis possible to construct only almost half of the sloping surface of theconvex portion 501 on the area corresponding to the first gap, that is,the rubbing-down portion 501 b on the area. Further, in this case, asshown in FIG. 7, by providing the light-shielding capacitive line 300and the junction layer 71 corresponding to the space between theadjacent pixel electrodes 9 a, it is possible to effectively shield onlythe rubbing-down portion 501 b, that is, to effectively shield thecorresponding portion of the convex portion 501 expected to be mostinfluenced by the nonuniformity.

As a result, according to the present exemplary embodiment, since theoperation failure of the electro-optical device caused by thenonuniformity can be substantially prevented, and since the rubbing-upportion 501 a of the convex portion 501 is not expected to be influencedby the nonuniformity remains to transmit the light contributing to theimage display, it is possible to enhance the pixel opening ratio, thatis, to maintain the bright image. Consequently, according to the presentembodiment, from the above-described point of view, an enhancement inthe quality of the display image can be obtained.

Further, by forming the narrow width portion 332 a′ at the positiondeviated from the center of the first gap, it is possible to enhance thedegree of freedom in the design of the electro-optical device and toeffectively prevent or substantially prevent the light from entering theTFT 30. The reason thereof is as follows.

That is, although the narrow width portion 332 a′ in the presentexemplary embodiment extends through the first gap between the adjacentpixel electrodes 9 a, it does not exist at the center thereof. For thisreason, for example, by using an area not provided with the narrow widthportion 332 a′ in the first gap, other wirings such as the capacitiveline 300 made of the same film as the narrow width portion 332 a′ can beformed parallel to the narrow width portion 332 a′ from a plan view.That is, the degree of freedom in design can be increased.

Further, in the above-described case, although the narrow width portion332 a′ is deviated from the center line, by adjusting the width of thebroad width portion 331 a′, for example, by broadening only one sidethereof or by broadening one side thereof more than the other side, itis possible to arrange the broad width portion 331 a′ as the gateelectrode at the center of the gap. In the present exemplary embodiment,as shown in FIGS. 5 and 6, it can be understood that the broad widthportion 331 a′ is broadened toward only one side. Hence, since the gateelectrode can be arranged at a position advantageous to enhance thelight-shielding ability irregardless of the position of the scanningline 330 a′, or since the scanning line 330 a′ can be arranged at anarbitrary position in the gap while arranging the gate electrode at aposition advantageous for improving the light-shielding ability, it ispossible to increase the degree of freedom in an arrangement of wirings,such as an arrangement of the scanning line 330 a′ and to obtain the TFT30 originally having a substantially high light-shielding ability.

In short, in the embodiment shown in FIGS. 5 and 6, while satisfying therequirements to enhance the quality of the display image, enhancing thedegree of freedom in design and decreasing the light leak current in theTFT 30, it is possible to adequately adjust/determine the arrangementbetween the channel area 1 a′ (or the TFT 30) and the gate electrode (orthe scanning line 330).

As described above, according to the electro-optical device of thepresent exemplary embodiment, since the scanning line, as the gateelectrode, has the broad width portion and the narrow width portion,while satisfying the above various requirements or a generalrequirement, such as high precision of the electro-optical deviceitself, it is possible to adequately adjust/determine the arrangementbetween the channel area (or the TFT) and the gate electrode (or thescanning line).

(Second Exemplary Embodiment)

Now, a second exemplary embodiment of the present invention is explainedwith reference to FIGS. 8 to 11. FIGS. 8 and 10 are plan viewsillustrating another exemplary embodiment different from that in FIG. 2in that a groove is formed on the TFT array substrate 10 and at least apart of the scanning line is buried in the groove. FIGS. 9 and 11 aresectional views illustrating a profile of the narrow width portion ofthe scanning line according to the second exemplary embodiment,respectively (FIG. 9 corresponds to FIG. 8, and a section taken along aline Z1–Z1′ in FIG. 8 corresponds to a section taken along plane Z1–Z1′in FIG. 9. Further, FIG. 11 corresponds to FIG. 10, and a section takenalong plane Z2–Z2′ in FIG. 10 corresponds to a section taken along planeZ2–Z2′ in FIG. 9). Further, FIG. 12 is a sectional view taken alongplane T–T′ in FIG. 10. Furthermore, since the basic construction andoperation, etc., of the electro-optical device of the second exemplaryembodiment are similar to those of the first exemplary embodiment,explanation about distinctive portions in the second exemplaryembodiment are mainly described below. Furthermore, the referencenumerals in FIGS. 8 and 12 indicate the same elements as in FIGS. 1 to 7referred to in the above description, when they indicate substantiallyequivalent elements.

First, in one aspect of the second exemplary embodiment, as shown inFIGS. 8 and 9, a groove 3G1 is formed along the scanning line in the TFTarray substrate 10. The groove 3G1 is formed except for the area wherethe semiconductor layer 1 a of the TFT 30 is formed. By thisconstruction, in consideration of only the grooves, the grooves 3G1 arearranged in a matrix shape from a plan view (see FIG. 8). Further, ascanning line 340 a is formed such that the narrow width portion 342 athereof is entirely buried in the groove 3G1 (see FIG. 9).

In another aspect of the second embodiment, as shown in FIGS. 10 and 11,a groove 3G2 is formed on the TFT array substrate 10, similarly to thegroove 3G1. However, preferably, a groove 3G2 is formed slightlynarrower than the groove 3G1. Further, a narrow width portion 352 a ofthe scanning line 350 a is formed along the groove 3G2. The narrow widthportion 352 a has a buried portion 352 aB of which a part is buried inthe groove 3G2 and a non-buried portion 352 aNB which is not buried inthe groove 3G2 and extends parallel to the buried portion 352 aB. Thenon-buried portion 352 aB is formed on the surface of the TFT arraysubstrate 10.

Further, in one aspect and another aspect of the second exemplaryembodiment, as shown in FIGS. 8 and 10, a groove 6G1 is formed in theTFT array substrate 10 along the data line. Furthermore, the data line 6a is formed to be entirely buried in the groove 6G1. In addition, thesemiconductor layer 1 a is also formed to be entirely buried in thegroove 6G1.

According to the electro-optical device of the second exemplaryembodiment constructed as above, the following effects can be obtained.First, since the whole part or a part of both of the scanning lines 340a and 350 a are buried in the grooves 3G1 or 3G2, as shown in FIGS. 9and 11, in this buried portion, the surface height of the baseinsulating film 12 and the height of the buried portion 352 aB of thescanning line 340 a and the scanning line 350 a are almost equal to eachother to maintain the leveling feature. By this, the leveling feature ofthe first to third interlayer insulating film 41 to 43 formed as theupper layers of the scanning lines 340 a and 350 a, or the pixelelectrode 9 a and the oriented film 16 can be well obtained. Therefore,in the second exemplary embodiment, for example, since a step along thenarrow width portion 342 a or the buried portion 352 aB does notsubstantially appear on the surface of the oriented film 16, the rubbingprocess can be very suitably performed on the oriented film 16 and thebad orientation can be drastically prevented or reduced. Furthermore, aneffect can be obtained that the light leakage caused by the badorientation and deterioration of the image quality based on the lightleakage.

Such effects on the portion along the data line 6 a can be obtainedbecause of the existence of the groove 6G1.

Further, in FIGS. 10 and 11, in particular, because of the existence ofthe non-buried portion 352 aNB, the following effects can be obtained.The effects are explained in detail below.

First, in the electro-optical device of the present exemplaryembodiment, generally in order to prevent or reduce deterioration of theelectro-optical material caused by the application of DC voltage and toprevent or reduce the cross-talk or flicker in the displayed image, aninverse driving method of inversing the polarities of voltages appliedto the respective pixel electrodes 9 a in a predetermined rule may beemployed. More specifically, so-called “1H inverse driving method” isexplained below.

First, as shown in FIG. 13( a), during the time to display image signalsfor the n-th field (n is a natural number) or frame, the polarity of theliquid crystal driving voltage indicated by + or − for each pixelelectrode 9 a is driven with the same polarity for every row.Thereafter, as shown in FIG. 13( b), when the image signals for then+1-th field or frame are displayed, the polarity of the liquid crystaldriving voltage for each pixel electrode 9 a is inversed and during thetime for displaying the image signal of the n+1th field or one frame,the polarity of the liquid crystal driving voltage indicated by + or −for each pixel electrode 9 a is not inversed, and each pixel electrodeis driven with the same polarity for every row. Then, the state shown inFIGS. 13( a) and 13(b) is repeated at the period of one field or oneframe. This is the 1H inverse driving method. As a result, whileavoiding deterioration of the liquid crystal caused by the applicationof DC voltage, it is possible to prevent image display with reducedcross-talk or flicker. Further, the 1H inverse driving method is moreadvantageous than the 1S inverse driving method to be explained later,in that there is no almost cross-talk in the vertical direction (Ydirection) in the drawing.

However, as can be understood from FIG. 13( a) and FIG. 13( b), in the1H inverse driving method, a horizontal electric field takes placebetween the pixel electrodes 9 a adjacent to each other in the verticaldirection (Y direction) in the drawing. In these drawings, an area C1where the horizontal electric field takes place is always in thevicinity of the gap between the pixel electrodes adjacent to each otherin the Y direction. If such horizontal electric field is applied, forthe electro-optical material to which a vertical electric field, i.e.,an electric field perpendicular to the surface of the substrate, isapplied, between the pixel electrode and the opposing electrode facingeach other, the operation failure can be caused by the bad orientationof the liquid crystal in the electro-optical material and by the lightleakage in the portion, which leads to a problem of decreasing thecontrast ratio.

With respect to the above, the area where the horizontal electric fieldis generated can be covered by the light-shielding film. However, inthis case, there is a problem that the opening area of pixels becomesnarrow in respect to the area where the horizontal electric field isgenerated. In particular, as the distance between the adjacent pixelelectrodes becomes small due to minuteness of the pixel pitch, suchhorizontal electric field increases, and thus this poses a seriousproblem in a higher precision electro-optical device.

In the aspect shown in FIGS. 10 and 11 of the second exemplaryembodiment, a step caused by the height of the non-buried portion 352aNB is formed between the pixel electrodes 9 a (that is, the adjacentpixel electrodes 9 a to which voltage of inverse polarity is applied)adjacent to each other in the vertical direction. Because of theexistence of this step, it is possible to intensify the verticalelectric field in the vicinity of an edge portion of the pixel electrode9 a arranged on the step and to weaken the horizontal electric field.More specifically, as shown in FIG. 12, the distance between thevicinity of the edge portion of the pixel electrode 9 a arranged on thestep 430 and the opposing electrode 21 becomes narrower by the height ofthe step 430. Therefore, in the area C1 where the horizontal electricfield is generated, the vertical electric field between the pixelelectrode 9 a and the opposing electrode 21 can be intensified.Furthermore, in FIG. 12, since the gap between the adjacent pixelelectrodes 9 a is constant, the intensity of the horizontal electricfield to be intensified with the gap getting narrow is constant.Therefore, by making the vertical electric field more prevalent in thearea C1 where the horizontal electric field is generated, it is possibleto prevent or reduce the bad orientation of the liquid crystal caused bythe horizontal electric field. Furthermore, because of the step 430 madeof the insulating film, the intensity of the horizontal electric fieldis weakened, and the portion of the liquid crystal affected by thehorizontal electric field is decreased by the amount of replacing thestep where the horizontal electric field exists. Therefore, theinfluence of the horizontal electric field on the liquid crystal layer50 can be reduced.

Further, in the above description, the 1H inverse driving method hasbeen explained but the present invention is not limited to such adriving method. For example, 1S inverse driving method of inversing thevoltage polarity at a period of a frame or a field for each column whiledriving pixel electrodes in a column with the potential of the samevoltage polarity may be employed in the present invention as the inversedriving method of which control is relatively easy and which enables thehigh quality image display. Furthermore, between the pixel electrodesadjacent to each other in both of the column direction and the rowdirection, the dot inverse driving method of inversing the voltagepolarity applied to each pixel electrode has been developed and can beapplied to the present invention.

Further, in the second exemplary embodiment, as shown in FIG. 2, theaspect in which the narrow width portion 342 a and 352 a is formed toextend through the center of the first gap between the adjacent pixelelectrodes 9 a has been explained. However, the present invention is notlimited to such a construction. That is, as shown in FIGS. 5 and 6, inthe aspect where the narrow width portion is formed to extend at theposition deviated from the center of the first gap, the grooves 3G1 or3G2 shown in FIGS. 8 to 11 may be formed in a combination. For example,the construction shown in FIGS. 14 and 15 may be employed. FIG. 14 is aplan view illustrating another aspect different from that in FIG. 2 inthat a groove is formed on the TFT array substrate 10, and the narrowwidth portion of the scanning line is deviated from the center of thefirst gap, and FIG. 15 is a sectional view taken along plane T–T′ inFIG. 14.

FIG. 14 is similar to FIGS. 5 and 6 in that a narrow width portion 362 aof a scanning line 360 a is deviated from the center of the long firstgap extending through the space between the adjacent pixel electrodes 9a, but FIG. 14 is different from FIGS. 5 and 6 in that the narrow widthportion 362 a is formed along a groove 3G1′ formed on the TFT arraysubstrate 10 and a broad width portion 361 a is formed to protrude onlydownwardly in FIG. 14. In this construction, the narrow width portion362 a of the scanning line 360 a is formed from the upper portion in thedrawing as viewed from the center of the first gap, and thus the narrowwidth portion 362 a is formed to be positioned right below the contacthole 85 for connecting the pixel electrode 9 a and the junction layer71. Further, the narrow width portion 362 a is formed to be entirelyburied in the groove 3G1′.

According to this construction, as shown in FIG. 15, the contact hole 85is formed on the scanning line 360 a formed to be buried in the groove3G1′. In other words, it is possible to form the contact hole 85 on theassumption that the step caused by the height of the scanning line 360 adoes not substantially appear on the surface of the third interlayerinsulating film 43.

In such a construction shown in FIGS. 14 and 15, in particular, anadvantage from the contact hole 85 which can be easily and securelyformed can be obtained. That is, assuming that a step due to the heightof the scanning line or the narrow width portion is generated on thesurface of the third interlayer insulating film 43, there is apossibility of a disadvantage in that the contact hole 85 may be formedon the vertex or on the ridge of the step. The present constructionovercomes such a drawback.

The above effects can be understood from the following point of view.That is, in the second exemplary embodiment, since the whole or a partof the scanning line is buried in the groove, and thus a step due to theheight of the scanning line does not substantially appear on the surfaceof the respective interlayer insulating film, the formation position orthe extending position of the scanning line need not be consideredparticularly. In other words, if the scanning line is between theadjacent pixel electrodes in the direction thereof, the scanning linemay be formed at any position. This is because, even when the formationposition or extending position of the scanning line is selected freelyand the contact hole is formed thereon, as described above, the contacthole can be relatively easily and securely formed due to the absence ofthe step.

Further, in case the narrow width portion has both the buried portionand the non-buried portion, it is preferable to form the groove suchthat the buried portion is positioned right below the contact hole 85.FIG. 12 corresponds to an example of such a construction.

(Third Exemplary Embodiment)

A third exemplary embodiment of the present invention is explained belowwith reference to FIGS. 16 to 19. FIG. 16 is a plan view illustratinganother aspect in that a shape of the data line is different from thatin FIG. 2. FIG. 17 is a sectional view taken along plane P–P′ in FIG.16, FIG. 18 is a sectional view taken along plane Q–Q′ in FIG. 16, andFIG. 19 is a sectional view taken along plane R–R′ in FIG. 16. Further,since the basic construction and operation of the electro-optical deviceof the third exemplary embodiment are similar to those of the firstexemplary embodiment, explanation about distinguishing features of thethird exemplary embodiment is mainly described below. Furthermore,reference numerals in FIGS. 16 to 19 indicate the same elements as inFIGS. 1 to 15 referred to in the above description, when they indicatessubstantially equivalent elements.

In the third exemplary embodiment, as shown in FIGS. 16 to 19, a dataline 6 a 1 includes a broad width portion 6 aW of which a portionoverlapping the TFT 30 is formed locally broad. Further, a width W1 of aportion extending along the data line 6 a 1 in the capacitive line 300,that is, the protruded portion 302, first, is broader than a width W2′of the portions except for the broad width portion 6 aW in the data line6 a 1 (in particular, see FIG. 17). Second, the width W1 of theprotruded portion 302 is almost equal to a width W6 of the broad widthportion 6 aW in the data line 6 a 1 (see FIG. 18). The channel area 1 a′of the semiconductor layer 1 a is positioned almost at the center in thewidth direction of the broad width direction 6 aW and almost at thecenter in the width direction of the scanning line 3 a. Furthermore, inthe third exemplary embodiment, as shown in FIGS. 16, 18 and 19, thebroad width portion 6 aW of the data line 6 a 1 is formed continuouslyfrom the portion overlapping the TFT 30 to the portion in which thecontact hole 81 to connect the semiconductor layer 1 a of the TFT andthe data line 6 a is provided, for each TFT 30 arranged in a matrixshape. In addition, in the third exemplary embodiment, as shown in FIGS.17 to 19, the light-shielding film 23 is formed on the opposingsubstrate 20. A width WS of one-by-one lattice of the light-shieldingfilm 23 is greater than that of the broad width portion 6 aW.

In the electro-optical device of the third exemplary embodimentconstructed like the above, the following effects can be obtained. Thatis, first, since the broad width portion 6 aW of the data line 6 a 1 andthe protruded portion 302 of the capacitive line 300 which is formedbroad exist on the TFT 30, so called a double light-shielding effect canbe obtained. Therefore, it is difficult for the light to enter thechannel area 1 a′ of the TFT 30, and thus the light leak current can bereduced or minimized.

In particular, in the third exemplary embodiment, the broad widthportion 6 aW of the data line 6 a also exists on the TFT 30 whileoverlapping the capacitive line 300. In this case, on the TFT 30, thelight-shielding ability corresponding to the integrated value of theirtransmittances can be obtained. Further, since the channel area 1 a′ ofthe semiconductor layer 1 a is positioned almost at the center in thewidth direction of the broad width portion 6 aW and almost at the centerin the width direction of the scanning line 3 a, the light-shieldingability can be enhanced.

Second, in connection with such excellent light-shielding ability, inthe third exemplary embodiment, as described above, the width W1 of theprotruded portion 302 of the capacitive line 300 and the width W6 of thebroad width portion 6 aW of the data line 6 a are less than the width WSof the light-shielding film 23 on the opposing substrate 20 (that is,WS>W1, WS>W6). According to this, the light entered from the upperportion of the TFT 30 is first shielded by the light-shielding film 23and is further shielded by the broad width portion 6 aW of the data line6 a. Furthermore, although passing through the broad width portion 6 aW,the incident light is next shielded by the protruded portion 302 of thecapacitive line 300. In short, in the third exemplary embodiment, sincetriple light-shielding is implemented, it becomes more difficult for thelight to enter the TFT 30.

Third, in the third exemplary embodiment, the broad width portion 6 aWof the data line 6 a is formed continuously from the portion overlappingthe TFT 30 to the contact hole 81 for each TFT 30 arranged in a matrixshape. Since the contact hole 81 is provided to connect thesemiconductor layer 1 a of the TFT 30 and the data line 6 a as describedabove, the capacitive line 300 cannot be formed in the portion. However,in the third exemplary embodiment, in the formation position of thecontact hole 81, the broad width portion 6 aW of the data line 6 aexists similarly to the upper portion of the TFT 30. Therefore,deterioration of the light-shielding ability caused by the absence ofthe capacitive line 300 can be compensated by the existence of the broadwidth portion 6 aW. In this connection, as in the third exemplaryembodiment, according to the aspect that the broad width portion 6 a isformed continuously on the TFT 30 and on the formation position of thecontact hole 81, since it is not necessary to broaden exceedingly theformation area of the broad width portion 6 aW, it is preferable not toincrease the inner reflection.

As described above, in the third exemplary embodiment, by thecombination of various effects, the possibility of the light incidenceto the channel area 1 a′ is drastically decreased, and the generation ofthe light leak current in the TFT 30 and consequently the generation ofthe flicker and the like on the image due to the light leak current canbe effectively suppressed, reduced or minimized.

(The Whole Construction of the Electro-Optical Device)

The whole construction of the electro-optical device according to thepresent exemplary embodiment constructed like the above is explainedwith reference to FIGS. 20 and 21. Further, FIG. 20 is a plan view ofthe TFT array substrate along with the respective elements formedthereon viewed from the opposing substrate 20 side, and FIG. 21 is asectional view taken along plane H–H′ in FIG. 20.

In FIGS. 20 and 21, in the electro-optical device according to thepresent exemplary embodiment, the TFT array substrate 10 and theopposing substrate 20 are arranged opposite to each other. A liquidcrystal layer 50 is inserted and sealed between the TFT array substrate10 and the opposing substrate 20 and the TFT array substrate 10 and theopposing substrate 20 are affixed to each other by a sealing material 52provided in the sealing area positioned around the image display area 10a.

In the outer area of the sealing material 52, a data line drive circuit101 to drive the data line 6 a by supplying image signals to the dataline 6 a at a predetermined timing, and the external circuit connectingterminals 102 are provided along one side of the TFT array substrate 10,and scanning line drive circuits 104 to drive the scanning line 3 a bysupplying scan signals to the scanning line 3 a at a predeterminedtiming is provided along two sides adjacent to the one side.

Further, if delay of the scan signals supplied to the scanning line 3 adoes not matter, the scanning line drive circuit 104 on only one side issufficient. Furthermore, the data line drive circuit 101 may be arrangedon both sides along the sides of the image display area 10 a.

The remaining one side of the TFT array substrate 10 is provided with aplurality of wirings 105 for connection between the scanning line drivecircuits 104 provided on both sides of the image display area 10 a.Further, at least one corner of the opposing substrate 20 is providedwith a conductive material 106 for electrical connection between the TFTarray substrate 10 and the opposing substrate 20. Furthermore, as shownin FIG. 21, the opposing substrate 20 having almost the same profile asthe sealing material 52 shown in FIG. 20 is bonded to the TFT arraysubstrate 10 through the sealing material 52.

In FIG. 21, after the TFTs for switching pixels, or wirings, such as thescanning lines, the data lines are formed on the TFT array substrate 10,and the oriented film is formed on the pixel electrodes 9 a. In additionto the opposing electrode 21, the oriented film is formed on theuppermost portion of the opposing substrate 20. Further, the liquidcrystal layer 50 is formed of the liquid crystal in which, for example,one kind or several kinds of nematic liquid crystal are mixed, and isoriented in a predetermined state between a pair of oriented films.

Furthermore, on the TFT array substrate 10, in addition to the data linedrive circuit 101 and the scanning line drive circuit 104, a samplingcircuit to apply image signals to the plurality of data lines 6 a at apredetermined timing, a precharge circuit to supply a precharge signalof a predetermined voltage level to the plurality of data lines prior tothe image signals, an inspection circuit to inspect the quality ordefects of the electro-optical device during production thereof or inshipping thereof and the like may be formed.

(Exemplary Embodiment of Electronic Apparatus)

Next, for an embodiment of a color display device of a projection typethat is an example of an equipment using the above-describedelectro-optical device as a light bulb, the whole construction thereof,in particular, the optical construction thereof is explained. FIG. 22 isa diagrammatic sectional view of the color display device of aprojection type.

In FIG. 22, a liquid crystal projector 1100 that is an example of thecolor display device of a projection type in the present exemplaryembodiment includes three liquid crystal modules including the liquidcrystal device in which the drive circuit is mounted on the TFT arraysubstrate, and further includes the respective light bulbs 100R, 100Gand 100B for RGB. In the liquid crystal projector 1100, when transmittedlight is emitted from a lamp unit of white light source such as a metalhalide lamp, the light is divided into the light components R, G and Bcorresponding to the three primary colors RGB by three mirrors 1106 andtwo dichroic mirrors 1108 and guided to the light bulbs 100R, 100G and100B corresponding to the respective colors, respectively. At this time,in particular, in order to prevent or reduce the light loss caused bythe long light path, the B light is guided through a relay lens system1121 composed of an incident lens 1122, a relay lens 1123 and an exitlens 1124. Then, the light components corresponding to the three primarycolors modulated, respectively, by the light bulbs 100R, 100G and 100Bare synthesized again by a dichroic prism 1112, and then are projectedas a color image to a screen 1120 through a projecting lens 1114.

The present invention is not limited to the above-described exemplaryembodiments, and instead may be appropriately varied without departingfrom the gist or the spirit of the invention known throughout the claimsand the specification. The electro-optical devices including suchvariation, for example, an electrophoresis apparatus or anelectro-luminescence display device, or the electronic apparatusincluding these electro-optical devices are also included in thetechnical range of the present invention.

1. An electro-optical device, comprising: a substrate; scanning linesabove the substrate and extending in a predetermined direction; datalines above the substrate and extending in a direction intersecting thescanning lines; thin-film transistors formed correspondingly tointersecting areas of the scanning lines and the data lines; pixelelectrodes formed correspondingly to the thin-film transistors; and arespective scanning line having a broad width portion as a gateelectrode in a portion facing a channel area of a respective thin-filmtransistor and a narrow width portion in another portion, the channelarea extending in a direction in which the data lines extend, therespective scanning line extending in a direction intersecting adirection in which the channel area extends, and the broad width portionextending in a direction intersecting a direction in which the scanningline extends and extending in a single direction or bi-direction inwhich the channel area extends, the broad width portion and the channelarea extending in a direction extending from the channel area to acontact hole, the contact hole electrically connecting the channel areaand the data line, the pixel electrodes being arranged in a matrixshape, the respective channel area being formed in an intersecting areain which a first long gap extending through a space between the pixelelectrodes sandwiching the scanning line and being adjacent to eachother and a second long gap extending through a space between the pixelelectrodes sandwiching the data line and being adjacent to each other,are intersected, the narrow width portion being formed at a positiondeviated from a center of the first gap, and the broad width portionbeing formed at the center of the first gap in the intersecting area. 2.The electro-optical device according to claim 1, the broad width portionbeing formed at a center of the second gap in the intersecting area. 3.An electro-optical device, comprising: a substrate; scanning lines abovethe substrate and extending in a predetermined direction; data linesabove the substrate and extending in a direction intersecting thescanning lines; thin-film transistors formed correspondingly tointersecting areas of the scanning lines and the data lines; pixelelectrodes formed correspondingly to the thin-film transistors; and arespective scanning line having a broad width portion as a gateelectrode in a portion facing a channel area of a respective thin-filmtransistor and a narrow width portion in another portion, the channelarea extending in a direction in which the data lines extend, therespective scanning line extending in a direction intersecting adirection in which the channel area extends, and the broad width portionextending in a direction intersecting a direction in which the scanningline extends and extending in a single direction or bi-direction inwhich the channel area extends, the broad width portion and the channelarea extending in a direction extending from the channel area to acontact hole, the contact hole electrically connecting the channel areaand the data line, grooves being formed in the substrate along thescanning lines, and the scanning lines being buried at least partiallyin the grooves directly or through an interlayer insulating film, thenarrow width portion having a buried portion buried in the groove andextending along the scanning line and a non-buried portion non-buried inthe groove and extending along the scanning line in parallel to theburied portion, and a base of the pixel electrode being positioned highalong the scanning line due to the non-buried portion.
 4. Anelectro-optical device, comprising: a substrate; scanning lines abovethe substrate and extending in a predetermined direction; data linesabove the substrate and extending in a direction intersecting thescanning lines; thin-film transistors formed correspondingly tointersecting areas of the scanning lines and the data lines; pixelelectrodes formed correspondingly to the thin-film transistors; arespective scanning line having a broad width portion as a gateelectrode in a portion facing a channel area of a respective thin-filmtransistor and a narrow width portion in another portion, the channelarea extending in a direction in which the data lines extend, therespective scanning line extending in a direction intersecting adirection in which the channel area extends, and the broad width portionextending in a direction intersecting a direction in which the scanningline extends and extending in a single direction or bi-direction inwhich the channel area extends, the broad width portion and the channelarea extending in a direction extending from the channel area to acontact hole, the contact hole electrically connecting the channel areaand the data line; and a capacitive line having a capacitor electrode ona pixel potential side connected to the pixel electrode to construct astorage capacitor and a capacitor electrode on a fixed potential sideopposing the capacitor electrode on the pixel potential side through adielectric film to constitute the storage capacitor, the capacitive linehaving a main line portion extending along the scanning line and aportion extending along the data line, a width of the portion extendingalong the data line in the capacitive line being equal to or broaderthan that of the data line, a portion overlapping the thin-filmtransistor in the data line being formed locally broad, and a width ofthe portion extending along the data line in the capacitive line beingbroader than a width of a portion not formed broad in the data line andequal to that of the portion formed broad in the data line.
 5. Theelectro-optical device according to claim 4, for each thin-filmtransistor, the data line being formed continuously broad from theportion overlapping the thin-film transistor to a portion in which thecontact hole is formed.